System of automatic block-signaling for electric railroads.



Patented Dec. 7, 1915.

e. H. BENJAMIN. SYSTEM, OF AUTOMATIC BLOCK SIGNALING FOR ELECTRIC RAILROADS'.

APPLICATION FILED APR-3.19M.

iTNESSES:

1W5 admv WM GEORGE HILLARD BENJAMIN, OF NEW YORK, N. Y.

SYSTEM OF AUTOMATIC BLOCK-SIGNALI1\TG FOR ELECTRIC RAILROADS.

Specification of Letters Patent.

Patented Dec. 7, H915.

Application filed. April 3, 1911. Serial No. 618,537.

To aZZ whom it may 00ncern Be it known that I, Gnonon HILLARD BEN- JAMIN, a citizen of the United States, residing at the city, county, and State of New York, have invented certain new and useful Improvements in Systems of Automatic BloclcSignaling for Electric Railroads, of which the following is a specification.

My invention relates to a system of automatic block signaling for electric railroads, and consists primarily in the means employed for connecting the'signal controlling devices in the track circuits, and secondarily in the means employed for obtaining sig* nal indications upon short blocks, the object of my invention being to improve and simplify such systems. p

The accompanying diagrams will serve to illustrate my invention. i

Figure 1 is a general view, illustrating a system in which the traffic rails are continuous and the signaling devices arranged to be controlled by cumulative drops of poten tial taken along two separate rails. Fig. 2

is a general view showing the same general system and illustrating a method of connecting and energizing short blocks.

Referring to the drawings; 5 indicates propulsion generator, shown in Fig. 1 as a direct current generator and in Fig. 2 as an alternating'currentgenerator; 6, feeder; 78 trafiic rails. In Fig. 1 the rails 78 are continuous and are I divided into blocks A, B, C, by means of crossbonds 9. In Fig. 2 the rails 7-8 are shown as divided by insulation 10.at the ends of a block section. Such division of the rails, however, only applies to that"portion of the. trackway where a short block or a plurality of short blocks are introduced.

In Fig. 2, D indicates short bl0cks;E, a block intervening between two short blocks D; and F, a block having thegeneral char acterlstios, so far as 001113111111ty.0f the rails,

etc, is concerned, of blocksA, B, C, of Fig. 1.. The short blocksD are each provided with an additional conductor 11 for. the propulsion current, and it will be observed that the rail 8 andconductor 11 are connected throughaconductor 12 to the central point of a bond 9, and further, that by means of the conductor 11, which may have the same resistance and reactance per foot.

as the rail 7, the resistance and reactance presented to the propulsion current 1n? blocks D is the same as would be presented 1n :1

block similar to A, B length. In the blocksD the divisional rail 7trans1nits no propulsion current, its place being taken by the conductor 11. It will be further observed that in the blocks D no crossbonds 9 are used, and that the sections of rail 8 and conductor 11 are connected as before stated, through the conductor 12 to the central points of bonds 9 of the adjacent sections, as for instance E and'F.

By the arrangement above described, short blocks can be introduced anywhere along the line or in yards, without in any wise interfering with the free passage of the propulsion current.

15 indicates signaling generator; Iii-17, feeders; 20, energy transformer, having its primary 21 connected across the feeders 16-l7, and its secondary 22 connected across the rails.

1 In the blocks A and B of Fig. 1, and E of Fig. 2, the energy transformer 20 is connected across the center of the block. In blocks D of Fig. 2 the energy transformer 20 is located at the right hand end, of the block. The purpose of placing the energy transformer in the center of the block is to reduce the losses due to resistance and reactance, which of course is not important in short blocks like D.

Situated at each end of the blocks A, B, of Fig. 1, and E of Fig. 2, is a signal controlling device 25. Such signal controlling device is constructed as a polyphase motor with two stator coils 26-27 and a rotor coil 28. The coil 26 is in series with the secondary 29 of a transformer 30. The primary of this transformer is formed of two coils 31 32. The terminals of the coil 31 are connected at a distance apart to the track 7, and the terminals of the coil 32 are connected at a distance apart to the track 8. By separating the terminals of the coils at their points of connection to the respecti e tracks, a definitediiference of potential will eXist be. tween the terminals of each coil, and these two difierences of potential will be added together, and the primary, made up of the coils 3132 of the transformer 30' will be excited by the added difference ofpotential. The coil 27 is in series with the secondary coil 33 of transformer 34, whose primary is connected through one terminal to the rail 7, and through the other terminal to the rail 8. [By reason of the arrangement of the transformers 30 and 34:, as above described,

or C of corresponding the potential of the signaling current impressed upon the track rail by the transformer is stepped up in the coils'26-27. The difference of potential in the coils 26-27 may be the same or diiferent, as desired. It

'will be understood, that the current traversing the coil 26, acting in conjunction with coil 27, will produce rotary movement of the coil 28 and thereby operate the signal controlling device to control the local circuit and the signal in such circuit.

The rotor-coil 28 of each-slgnal controlling device is provided with an arm 36, adapted to coact' with contact plate-37 to control a local circuit 38, including a signaling device39 and battery tO.

I In the short blocks D (Fig. 2) the signal controlling device 25 has the stator c0il'27 connected as in Fig. 1, and the stator coil 26 connected in series with the secondary of a transformer 41, whose primary 4:2 s connected across the feeders 1 (517.

I have not shown in the circuits of the various transformers, eitherreactance or re sistance fixed or adjustable. It will of course be understood by those to whom this specification is addressed, that such reactance and resistance may be employed for type.

determining the phase of the currents excited in the stator coils, etc. Such illustrative matter has been left out of the present case in orderto avoid needlessly complicating the drawings.

7 and it is desired to use two signal controlling devices in series, as shown in Fig. 1, it is often advisable to use the inductance crossbonds. I have not shown such type of bonds as they are well known in the art,

' and such illustration would not convey anything new.

Where short blocks are coupled to long blocks, as shown in Fig. 2, and the blocks segregated by insulation, the type of crossbond is immaterial, and a non-inductive bond will serve the purpose. \Vhere, however,the insulation between the rails is not used, which is a possible condition,'inductancecrossbonds 41 should be substituted for I the non-inductive bonds, the tap being from the center point as shown in left hand block D (Fig. 2).

The operation of a system having the general features illustrated and'described, is now so well understood, that itis not considered necessary to make any specific reference thereto.

Having thus described my invention, I

claim 1. In a system of automatic block signaling, a source of signaling current, a trackwaydivided into block sections, means for impressing signaling current upon the block sections, a signal controlling device located at each end of each block section, each signal controlling device consisting of a polyphase motor having stator coils and a rotor coil; one of said stator coils energized by a current due to the added difference in potential between the terminals of two coils, one of said coils having its terminals connected at a distance apart to one rail and the other of said coils having its terminals connected at a distance apart to the other rail of the trackway, and the other of said stator coils by the difference in potential between the terminals of a coil, one terminal of which is connected to one rail and the other terminal to the opposite rail of the trackway, a signal, and a local circuit controlled by both signal controlling devices.

2. In a system of automatic block signaling, a source of signaling current, a trackway divided into block sections, means for impressing signaling current upon the block sections, means for stepping up the signaling current at each end of each block section, a signal controlling device located at each end of each block section, each signal controlling device consisting of a polyphase motor having stator coils and a rotor coil: one of said stator coils energized by a current due to the added difference in potential between the terminals of two coils, one of said coils having its terminals connected at a distance apart to one rail and the other of said coils having its terminals connected at a distance apart to the other rail of the trackway, and the other of said stator coils by the difference in potential between the terminals of a coil, one terminal of which is connected to one rail and the other terminal to the opposite rail of the trackway, a signal and a local circuit controlled by both signal controlling devices.

3. In a system of automatic block signal- Way divided into block sections, means for impressing signaling current upon the block sections, two step-up transformers at each of the block sections, one of each pair of said transformers having its primary divided into two sections and such sections respectively connected to shunt to short lengths of opposite rails and one of each pair of transformers having its primarv connected across the rails, signal controlling devices located at each end of the block sections, each of said signal controlhng (levlces consisting of a polyphase motor having stator coils and a rotor coil, one of such stator coils connected across the secondary a source of signaling current, a trackof the first named transformer and the other of said stator coils connected across the secondary of the second named transformer,

and a local circuit and a signal in the local circuit controlled by said signal controlling devices.

4. In a system of automatic block signaling, a source of signaling current, a trackway divided into block sections, means for impressing signaling current upon the block sections connected across the center of each block section, a signal controlling device located at each end of each block section, each signal controlling device consisting of a polyphase motor having stator coils and a rotor coil; one of said stator coils energized by a current due to the added difi'erence in potential between the terminals of two coils, one of said coils having its terminals connected at a distance apart to one rail and the other of said coils having its terminals connected at a distance apart to the other rail of the trackway, and the other of said stator coils by the difference in potential between the terminals of a coil, one terminal of which is connected to one rail and the other terminal to the opposite rail of the trackway, a signal and a local circuit controlled by both signal controlling devices.

5. In a system of automatic block signaling, a source of propulsion current, a feeder conductor, track rails divided into block sec tions and conductively continuous for all currents, a source of signaling current, means for impressing signaling .current upon each block section, signal controlling devices located at each end of each block section, each of the signal controlling devices consistitng of a polyphase motor having stator coils and a rotor coil; one of said stator coils energized by a current due to the added difference in potential between the terminals of two coils, one of said coils having its terminals connected at a distance apart to one rail and the other of said coils having its terminals connected'at a distance apart to the other rail of the trackway, and the other of said stator coils by the difference in potential between the terminals of a coil, one terminal of which is connected to one rail and the other terminal to the opposite rail of the trackway, a signal, and a local circuit controlled by both signal con trolling devices.

6. In a system of automatic block signaling, the combination of a source of propulsion current, a trackway of which the rails are continuous for all currents, bonds dividing the trackway into block sections, means for impressing signaling current upon each of the block sections, two transformers at each end of each block section, one of said transformers having its primary formed of two coils, one of said coils connected in shunt to one rail and the other of said coils connected in, shunt to the other rail, and the other transformer having its primary connected through its opposite terminals to opposite rails, signal controlling devices at each end of the block sections, each of such signal. controlling devices having two stator coils and a rotor coil; one of said stator coils energized by the current in the secondary of said first named transformer and the other of said coils energized by the current 1n the secondary of said second named transformer, a signal, and a local circuit controlled by both signal controlling devices.

7. In a system of automatic block signaling, the combination of track rails, a local c rcuit, a signal in the local circuit, and a signal controlling device; said signal controlling device having stator coils and a ro tor coil, one of said stator coils connected in series with the primary of a transformer, said transformer having two primary coils, one of said primary coils having its terminals connected a distance apart to one rail of the trackway, and the other primary having 1ts terminals connected a distance apart tothe other rail of the trackway, and said prnnarles wound to produce an added difference of potential, and the other stator coil connected in series to the secondary of a transformer having the terminals of its primary connected one to one rail and the other to the other rail, said signal controlling device adapted to control the local circuit and the signal therein.

8. In a system of automatic block signaling, a source of signaling current, a track way divided into block sections, means for impressing the signaling current upon the block sections, signal controlling devices lo cated at each end of the block sections, each of said signal controlling devices consisting of a polyphase motor having stator coils and a rotor coil, a transformer having its primary connected across the track rails and its secondary across one of the stator coils, a transformer having its primary divided into two coils, one of said coils connected a distance apart along one track rail and the other coil connected a distance apart along the opposite track rail and said coils wound in the same direction, and its secondary connected to the other stator coil, a signal, and a local circuit controlled by both signal controlling devices.

9. In a block signaling system, in combination with an electric railroad having both rails conductively continuous for all currents, sources of alternating current connected across the rails at intervals, bonds connected across the rails at points between said cources, two transformers located at each end of said block sections and between the bonds of the block sections, each of said transformers having magnetic cores, one of said transformers having a plurality of pri- 10 blocksection, each of said signal controlling devices normally energized by the collective Copies of this patent may be obtained for action of the secondary currents from the two transformers, a signal, and a local circuit controlled by both signal controlling devices.

In testimony whereof, I afiix my signature in the presence of two Witnesses.

GEO GE IIILLARD BENJAMIN, Vitnesses HELEN E. KonLscr-r,

CHARLES V. DUNN.

five cents each, by addressing the Commissioner of Patents Washington, D. C. 

